Lock and fastening device



..Au g.7, 1945.

L. W..YOUNG V LOCK AND FASTENING DEVI CE Filed 0011.15, 1942 Zea/card MPatented Aug. 7, 1945 a I I Look AND FASTENING Device I Leonard WeareYoung, Northwood, England Application c'tober15, 1942, Serial Nor462,151?

In Great Britain 0ctoberl5, 1-941 4 claims. ,(Ql. zet -#340? Thisinvention relates to a'nimproved lock-"or fastening device,]which forconvenience in'the ensuing description will 'be referred to as a .1 l. si i *In a latch according to the present invention a bolt, projection orlike -=member'to be secured (for convenience hereinafter referred to as'a bolt") is engageableby aslot in a 'camplaterotatable on a basejunderthe-influenceof the entering bolt, the cam plate beingengaged by areleasable catch operable to securethe cam plate-in such a position that'i'ts 'slot prevents withdrawal ofthe The invention hasaparticularimbodimerit in a device for fastening a. cowling,-'panel orhatch on anaircraft.

V order thatit' maybe clearly undrstood'and readily carried'into effect,the invention ishere inafter described with-reference to the accompanying'diag'rammatic drawing, of'whi'ch: Figure 1 is an end elevationof a latch show ingabolt engagedther'ebyy l Figure 2 is, asection takenon ofFi ure1;'while Y Figure 3'is a viewsimilar' to Figure 2 but showingthe latch in its di'sengaged condition. The latch includes'a bas'epa-Ift 4 which has a slot 5 leading-into it from one edge. The slot 5 isintended to receive the bolt 6. The arrangement will generally be suchthat the-base plate is screwed or otherwise secured to aframeme'rm bersurrounding the movablecowling, panel, hatch or door, whereas the'bolt 6is provided on the hinged or other movable member which fits thesurrounding framework; and it will be understoodthat the slot 5 needs tobe so disposed that the bolt 6 enters the slot as the hinged or movablemember is closed. The base has formed in it a recess L within whichthere is mounted a flat cam plate 8 which is secured by and turns theuse 11 1:

about the pivot 9. The pivot 9 is eccentric both in relation to the camplate 8 and the recess 1, and the cam plate 8 is thus free to swingaboutthe pivot 9 within the limits defined by the recess. The cam plate8 is urged by the small coil spring ill to the limit of itsanticlockwise movement about the pivot 9, which position is of coursedetermined by engagement of the cam with the lefthand side of therecess 1. In that setting a slot II in the cam plate 8 has its open endin register with the slot 5 of the base. The parts are so shown inFigure 3, which illustrate the lock in the disengaged condition readyfor the reception of a bolt such as 6.

When the bolt 6 enters the slot 5 it eventually engages the righthandedge'of the slot n ofthe cam'plate, which thus serves to overcome theforce of the spring ID and to turn the cam plate 8 clockwise about thepivot 9 into the 'position shown in Figure 2, For locking thelatch inthe positionshown in Figure 2, with the boltf fully engaged, there isprovided a slidable catch l2 which is guided in the slotl3, and which isurged-inwardly by the spring l4. The spring 14 causes the nose ofthecatch l2 tobe'ar'on the end of the cam: and consequently-it followsthat "the catch "snaps into theslot'll immediately it comes,'duringclockwise rotation of the cam plate 8, into register with the catch.

For disengagement of the latch, itsuffices t'e release the catch 12,which is'urged'outwa'rdly against the pressure of the spring l4bymanipulation of the handle l5, which swingsabout the pivot IE on thebase plate 4. The handle 15 continues inwardly "as'the catch-actuatinglever H, which can be moved angularly within the limits defined bythe"i'slot I ll. At its inner end the lever I1 has a circular endportion 19 which fits a' complementary slot formed in the edge of thecatch 1'2. 0n release of the catch [2 from the slot H of the 'cam' plate8 the spring l0 tends to rotate the cam plate "anticlockwise and therebyto disengagethe latch, urging thebolt 6 outwardly. 1 P i a It will beobserved'that the slot ll acts as the equivalent of a combined strikerand locking jaw. Thus, the striker is'the righthandedgeof the slot :Hwhich is engaged bythe bolt 6 as the-bolt enters the slot 5 with theparts in the position shown in Figure 3. Continuing the analogy. thelefthand edge of the slot ll comprises the looking jaw which liestransversely across the slot 5 to hold the bolt 6 down .at the bottom ofthe slot 5, as shown in Figure 2.

It is contemplated that the handle l5 may be actuated by any convenientform of remote control cable. f

A manufacturing point which is worthy of mention is that for the bestresults the angle of engagement between the edge I2A of the catch l2 andthe righthand or striker edge of the slot ll of the cam plate is fairlycritical. Thus, in the fully-engaged position as shown in Figure 2 theedge I2A should be inclined to the righthand or striker edge of the slotH at an angle of approximately 10". If that angle is very much less than10 the latch is diflicult to release under load; while, conversely, agreater angle tends to permit the latch to release itself under heavyloads. It is also preferable that the inner end of the catch l2 shouldnot abut the bolt 6 in the fully-engaged condition of the latch, for ifit does slight wear will make the parts slack.

It is an important feature of the latch device according to the presentinvention that, due to the angle at which the catch [2 operates, thebolt is actually securely gripped by the cam plate, with the result thatrattle is prevented and any vibration which occurs between the bolt andthe latch device results in the bolt being gripped the more tightly.

The spring Hi can be sufficiently strong to cause ejection of the bolt 6on release of the catch.

sponding slot and mounted for eccentric move- 'ment in the recess toprovide a latch-openposition with'- the slots in registry and alatch-closed The latch device can be easily adapted for -ordi-.

nary household doors, and is eminently suitable for automobile doors,bonnet catches, et cetera.

The plate indicated in Figure 1 by reference:

numeral I9 is merely a cover plate which'is bolted Though in all casesthe cover to the base plate. plate is preferable, it may be dispensedwith if the base plate is to be outermost when the latchis mounted.

What I claim is: r

1. A latch device for securely engaging a bolt engageable with anddisengageable' from the latch, comprising a base plate having a recessand provided witha slot leading in from an edge and communicating withsaid recess for the reception of the engageable bolt; a cam plateeccentrically mounted for rotation in the recess of said base plate; aslot leading inirom an edge of said rotatable cam plate; the cam plateby engagement with thewall of said recess serving .to define a limitposition in rotation of said cam plate, in which limit position the openend of the'cam slot is in register with the slot of the base plate toreceive the entering bolt; and releasable catch means engageablewith theslot of said cam'plate to secure it'with its slot lying across the baseplate slot to close the latter and prevent withdrawal'of the bolt. 1 v

2. A bolt latch, including a. base formed with a recess having an edgewall and .formed" with an entering slot, :a cam plate formed. withacorrespondingslot-and mounted for-eccentric move- ,5

ment in the recess to provide a latch-open position with the slotsin'registry anda latch-closed position with the slots out of registry,the cam plate being limited in movement to latch-open position bycontact-with a part of the'wall of the base recess, a spring bearingbetween thewall of the recess and thecam plate to'move the latter whenfree into that contact with the wall of the position with the slots outof registry, the cam "plate being limited in movement to latch-openposition bycontactwith a part of the wall of the base recess, a springbearing between the wall of the recess and the cam plate to move thelatter when free into that contact with the wall of the recess tonormally maintain thecam plate in vlatch open position, and a member.movable in the base to automatically enter the slot in the cam platewhen the latter is in latch-closing position, saidmember when in saidslot holding the spring under compression for automatically moving thecamplate to latch-open position when the member has been Withdrawn fromthe slot.

,4. A boltv latch, including a baseiormed with a recess having an edgewall -and,f ormed with-an enteringslot, a cam plate formed with acorresponding slot, and mounted for eccentric movement in the recess toprovide a latch-open posirecess to normally maintain the cam plate inlatch-open position, a member movable in the base to automaticallyrenterthe slot in the cam plate when the latter is in latch-closing position,said member when in saidslot holding the spring under compression forautomatically moving the camplate to latch-open position when the memberhas been withdrawn from theslot, and means fonwithdrawingthe'member fromthe slot to a position to bear -on and exert pressure against the edgeofthe cam plate in all non-latch-closing positions-of said plate"- a r ia LEONARD WEARE YOUNG.

